U.S. Army Corps updates CPRA on Lower Mississippi comprehensive study; chief’s report targeted for Dec. 2027

Colonel Colin Jones of the U.S. Army Corps of Engineers told the Coastal Protection and Restoration Authority board on Feb. 19 that the Lower Mississippi River Comprehensive Management Study is progressing through alternatives development and stakeholder engagement toward a chief’s report planned for December 2027.

Jones said the study — authorized in the Water Resources Development Act of 2020 (section 213) — covers the river from Cape Girardeau, Missouri, to the Gulf of Mexico, roughly 975 river miles. He told the board the Corps received additional authorization in WRDA 2022 (section 8343) to proceed with 100 percent federal funding for the study and that the program has a $25,000,000 appropriation intended to support a five-year study aiming for actionable recommendations, including operational modifications and potential construction proposals.

The Corps reported extensive public and interagency engagement: an inventory of existing studies and models, a governance structure that meets quarterly with state and federal partners, and more than 32 public meetings across the seven-state study area. Jones said the Corps is building hydrologic and sediment models for both the Lower Mississippi and the Atchafalaya to test a range of measures. Early modeling has flagged “dynamic operation” of the Old River Control Complex as a promising measure to evaluate whether different flow splits between the Mississippi and Atchafalaya might yield flood-risk, environmental or navigation benefits; Jones said any such operational changes would require detailed evaluation and could lead to updates to water-control manuals.

Jones emphasized that the scale of the effort requires broad collaboration. He named the New Orleans District as lead and said the study team is coordinating across six Corps districts, three divisions and multiple federal agencies, alongside 44 federally recognized tribes; he also noted state partnering groups that include CPRA representatives and said those groups meet in April and October. The Corps has posted a public scoping report that summarizes comments received to date and is maintaining a stakeholder database via the study website for routine updates.

Board members asked several technical and policy questions. Colonel Jones and Corps staff said they have built an initial funding profile for the study, that existing appropriations should carry work into the summer but the Corps has requested an additional $4,000,000 for FY2025 and indicated a capability of $7,000,000 in FY2026 to sustain the schedule. Jones said the $25,000,000 study budget is scoped to be sufficient for completion of the study but that additional funds would be required to implement any tiered follow-on investigations that the study might recommend.

Other topics discussed included dredging options for ecosystem restoration, modification of dredging and flow management to improve long-term sustainability, the Corps’ ongoing saltwater-mitigation review for the Mississippi River Ship Channel (including the underwater saltwater sill), and the Neptune environmental-structure work (planned updates to maintain lower flow regimes like those seen in 2019). Jones repeatedly encouraged state and local partners to provide input early in the alternatives process so the Corps can incorporate those concerns into modeling and environmental review.

Colonel Jones closed by directing stakeholders to the study website and stakeholder listserv (via the QR code he displayed) for updates and public- engagement opportunities.